| 摘要 |
1,217,682. Benzopyran derivatives. BUSH BOAKE ALLEN Ltd. 11 April, 1968 [27 April, 1967], No. 19556/67. Heading C2C. [Also in Division A5] The invention comprises compounds of the general Formula I wherein R 1 = alkyl C 1-4 , R 2 =H or alkyl C 1-4 , except that when R 1 = CH 3 , R 2 does not equal H. They are prepared subjecting a trans-#- ionone of the general Formula II wherein R 1 or R 2 are as defined above, to electromagnetic radiation of wavelength less than 400 mÁ until at least 20% by weight of the compound of Formula II has been converted to the compound of Formula I, or the compound of Formula I in which R 1 and R 2 are as defined above and in addition R 1 =CH 3 when R 2 =H, may be prepared by heating the corresponding compound of Formula II to 120-200‹ C., distilling the product therefrom at a reduced pressure using a reflux ratio that is sufficiently high for the isolated product to contain at least 20% by weight of the desired compound of Formula I. The novel and known compounds of Formula I are used as the ingredients in perfumery compositions. |
